Summary

The data in this series of studies were assembled by an
interdisciplinary research team led by Myron Gutmann of the University
of Michigan between 1995 and 2004, as part of a research project
funded by the National Institute of Child Health and Human Development
(Grant Number R01HD033554 to the University of Michigan). The goal of
the project was to amass information about approximately 500 counties
in 12 states of the Great Plains of the United States, and then to
analyze those data in order to understand the relationships between
population and environment that existed between the years of about
1870 and 2000. The data distributed here are all data about
counties. They fall into four broad categories: about the counties,
about agriculture, about demographic and social conditions, and about
the environment. The information about counties (name, area,
identification code, and whether the project classified the county as
part of the Great Plains in a given year) is embedded in each of the
other data files, so that there will be three series of data
(agriculture, demographic and social conditions, and environment),
containing individual data files for each year for which data are
available. The United States Census of Agriculture has been conducted
since 1850 on a regular schedule that was decennial until 1920, and
more frequently thereafter (every five years from 1925 to 1950, then
in 1954, 1959, 1964, 1978, and every five years since 1982). The
agricultural data included in this collection consist of a single data
file for each agricultural census year between 1870 and 1997 that
includes selected material compiled as part of the United States
Agricultural Census. The county-level agricultural data produced by
the United States government as part of the census constitute a
consistent series of measures of changing agriculture and land use.

Time Period(s)

Date of Collection

Data Collection Notes

Sample

The first comprehensive United States Census of
Agriculture in 1850 imposed a limit below which no tract of land was
to be considered a farm. If the value of produce from small farm lots
fell below $100 in value, they were to be excluded from the count of
census farms. In 1870, the minimums rose to reflect economic change
and to help sort out some of the confusion that emerged in the South
with emancipation, including the subdivision of plantations and
attendant uncertainties in proprietorship. The preamble to the 1870
census declared that "[n]o farm will be reported of less than three
acres, unless five hundred dollars' worth of produce has actually been
sold off from it during the year." This same definition was applied in
1880 and 1890.

In the 1900 preamble, census officials
explained a return to the original standard of 1850 and offered some
cautionary advice. In reviewing the changing definition of census
farms they noted that in "no [agricultural] census of the country had
one-half of the farms reported products of a value of $500, and the
proportion that had sold products of that value was much smaller. The
land occupied and the products secured by very many persons devoting
their entire time to caring for small dairies, apiaries, florists'
establishments, and kindred agricultural establishments were omitted
from reports, although those persons were properly included in the
occupation tables as dairymen, apiarists, florists, etc." Because of
these omissions from tabulated results in 1870, 1880, and 1890, census
marshals issued revised instructions to enumerators in 1900 that were
far more inclusive. This occupational and self-declared basis for
defining farms is further clarified by the explicit inclusion of
market-gardens, orchards, nurseries, cranberry marshes, greenhouses
and city dairies, provided, [emphasis in the
original] the entire time of at least one individual is devoted to
their care.

By 1910, size and production minimums
returned in a definition that retained language about farms as the
agricultural operations of self-described farmers, with the added
provision that they again be tracts of farmland at least three acres
in size, no matter what the value of their produce, or if they fell
below the size minimum, that they employ the continuous services of at
least one person or produce at least $250 worth of farm products. This
definition was applied again in 1920, 1925, 1930, 1935, 1940, and
1945. However the value of production for farms under three acres was
not adjusted for inflation or deflation. The inclusion or exclusion of
very small farms in the census during these years relied, in part, on
changes in the price of agricultural commodities.

In 1950, farms of three or more acres were included in the
census only if the value of their produce from the previous crop year,
in 1949, amounted to $150, and similarly operations under three acres
in size were included only if they met the minimum of $150 in sales
from the previous year.

In 1959, the farm size and
product value minimums were adjusted again. The farm size minimum was
raised to ten acres, with sales of at least $50, and if farms fell
below ten acres, they were required to have estimated sales of at
least $250. Farms that fell below either of these product value
minimums were included in the census if they could be expected to meet
them under normal conditions. The same census definition of census
farms was applied in 1964.

The biggest change in
process came in 1969 with the switch from face-to-face enumeration to
enumeration by mail. Nonsample "short" forms were mailed to every
respondent on the Census Bureau's mailing list, a list furnished by
the United States Department of Agriculture. By law, everyone on the
list was required to respond to the nonsample form. Respondents who
reported sales or acreage above specified levels on nonsample forms
were then sent correspondence requesting additional sample data. To
limit respondent burden, the nonsample form included only questions to
be reported at the county level. All county-level data are based on
the nonsample form.

The biggest change in
definition occurred in 1974 when the acreage criterion was dropped and
a farm was defined as a place from which $1,000 in agricultural
products was produced and sold, or normally would have been sold. The
use of sales as the basic criterion meant that operations that focused
on household use or non-commercial distribution were no longer
regarded as farms. It is estimated that this change defined 300,000
farms out of existence nationally, an estimate made more precise by
the count of farms using both definitions in the 1974 Agricultural
Census and the 1980 Population Census (Bruce L. Gardner, American
Agriculture in the Twentieth Century: How It Flourished and What It
Cost. Cambridge: Harvard University Press. 2002: 51-52). The $1,000
sales criterion persisted until the end of the twentieth
century.

Adjustments were made to enumeration by
mail in 1978 to improve coverage, including a revised mail list and
the adoption of a direct area enumeration sample, including the use of
aerial photography, as a data checking method.

In
1982, 3,653,000 nonsample forms were mailed in late December to
individuals, businesses and organizations on the mail list. Data
collection included a reminder card and five follow-up letters.
Further follow-up was conducted by mail and telephone for
nonrespondents in 14 states, and adjustments made to the final
results. All new farm successors reported by former operators were
researched to see if they had been included in the census mailing.
Report forms mailed to successor addresses not previously on the mail
file improved the coverage of the results.

Since
1987, coverage evaluation reports have accompanied the publication of
the agricultural census to provide estimates of the completeness of
the enumeration. In 1997, the use of post-census sampling by the USDA
increased the count of United States farms from 1.97 to 2.06
million.

Universe

All the counties in the 12 Great Plains states of the
United States (Colorado, Iowa, Kansas, Minnesota, Montana, Nebraska,
New Mexico, North Dakota, Oklahoma, South Dakota, Texas, and
Wyoming).

Unit(s) of Observation

county

Data Source

HISTORICAL, DEMOGRAPHIC, ECONOMIC, AND SOCIAL DATA: THE
UNITED STATES, 1790-1970 (ICPSR 0003)

Census volumes for pertinent years by the United States
Department of Agriculture

Census volumes for pertinent years by the United States
Bureau of the Census

Data Type(s)

Mode of Data Collection

Original Release Date

2005-06-22

Version Date

2005-06-22

Notes

The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.

This study was originally processed, archived, and disseminated by Data Sharing for Demographic Research (DSDR), a project funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).